All currently operating internal combustion piston engines are based on either:    1) The Otto cycle which requires a near stoichiometric mixture at all power levels to achieve near constant volume combustion with spark ignition. To maintain such a mixture ratio at part power, the fresh air intake must be throttled. This lowers efficiency by power used for cylinder filling. Otto cycle efficiency is limited by compression ratio, fuel octane number and knock.    2) The Diesel cycle requires compressing air to high pressure and temperature such that when its fuel injectors spray fine droplets into the hot air, they quickly evaporate and burn. Good atomization requires a high-pressure fuel pump and fuel injectors. To complete combustion as fast as it takes to inject the fuel (called cut-off ratio), a high cetane number fuel is required. The combustion process takes place during piston expansion, which results in the Diesel cycle having constant pressure heat addition. This is less efficient than constant volume heat addition as is possible when igniting a pre-evaporated air-fuel mixture, as in the Otto cycle. At full power, the cut-off ratio increases, which reduces efficiency and presents the possibility of incomplete combustion and air pollution by unburned hydrocarbons leaving the exhaust pipe. Small diesel engines for lawnmowers, chainsaws etc. do not exist because high-pressure fuel injectors cannot dispense small quantities of fuel. At cold temperatures the diesel fuel does not atomize nor evaporate well, and has a tendency to gel which explains its cold starting problems. The diesel engine is usually more efficient than a spark ignition engine and diesel fuel tax is less than gasoline tax. The lubricating property of Diesel fuel reduces cylinder wall wear, unlike gasoline, which dissolves the oil film from the walls. This makes the Diesel engines last longer than gasoline engines. Therefore the diesel engine is preferred for long distance hauling. Note: service problems are mostly related to their fuel-injector systems.
In the automotive, general aviation and small engines industry, reciprocating piston engines are mostly used because of their efficiency and high power to weight ratio. Spark ignition engines based on the Otto cycle are currently the lightest and the least expensive. Their thermal efficiency increases with design volumetric compression ratio (rv), which ranges from 7 to 11 and requires a corresponding increase in fuel-octane number from 80 to 100, to prevent pre-ignition and knock, and therefore fuel cost. Very high compression ratio fuel-efficient spark ignition engines are used in general aviation aircraft because their fuel weight is limited, therefore aircraft range and endurance depend on high fuel efficiency. At most airports only 100 octane Low Lead avgas and jet fuel are made available. For years the FAA has been trying to discontinue providing poisonous 100 Low Lead avgas by replacing such engines with a low cost, low maintenance, light weight, efficient diesel engine operating on jet fuel. Up till now this has not yet materialized. However the CIBAI engine might be a viable substitute as it can be operated efficiently on a wide range of liquid and gaseous fuels!
To extend the life of our hydro-carbon fuel reserves and minimize the atmospheric carbon-dioxide buildup there is a need for engines to operate on the CIBAI cycle to: accept a wide range of fuels, be more fuel efficient, reduce air pollution by unburned hydrocarbons, eliminate maintenance intensive components such as spark ignition systems and high-pressure fuel injectors, increase the range of general aviation aircraft and eliminate the need for poisonous 100 Low Lead avgas.